bluetooth - BlueZ LE 远程使用功能

问题描述

我正在使用 BlueZ 来处理 BLE 设备。我已经从源代码编译它，并围绕它编写了一个包装器。

我正在寻找这个微小的信息：

“LE 读取远程使用的功能”命令有什么用？
它可以读取哪些功能？
这对于连接到 BLE 设备是强制性的吗？
连接后禁用查询是否安全？
是否可以增加接收此命令响应的超时时间？

我的问题是我的解决方案已经适用于某些设备（可以连接到它们），但是对于特定设备，很多时候连接由于超时而失败。

当连接失败时，我用btmon创建了一个嗅探：

# btmon
Bluetooth monitor ver 5.50
= Note: Linux version 4.19.97-v7l+ (armv7l)                            0.742019
= Note: Bluetooth subsystem version 2.22                               0.742027
= New Index: AA:BB:CC:DD:EE:FF (Primary,UART,hci0)              [hci0] 0.742030
= Open Index: AA:BB:CC:DD:EE:FF                                 [hci0] 0.742033
= Index Info: AA:BB:CC:D.. (Cypress Semiconductor Corporation)  [hci0] 0.742035
@ MGMT Open: bluetoothd (privileged) version 1.14             {0x0001} 0.742038
@ MGMT Open: btmon (privileged) version 1.14                  {0x0002} 0.742321
< HCI Command: LE Set Scan Parameters (0x08|0x000b) plen 7   #1 [hci0] 4.737267
        Type: Passive (0x00)
        Interval: 60.000 msec (0x0060)
        Window: 30.000 msec (0x0030)
        Own address type: Public (0x00)
        Filter policy: Ignore not in white list (0x01)
> HCI Event: Command Complete (0x0e) plen 4                  #2 [hci0] 4.737714
      LE Set Scan Parameters (0x08|0x000b) ncmd 1
        Status: Success (0x00)
< HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2       #3 [hci0] 4.737767
        Scanning: Enabled (0x01)
        Filter duplicates: Enabled (0x01)
> HCI Event: Command Complete (0x0e) plen 4                  #4 [hci0] 4.738160
      LE Set Scan Enable (0x08|0x000c) ncmd 1
        Status: Success (0x00)
> HCI Event: LE Meta Event (0x3e) plen 42                    #5 [hci0] 6.099681
      LE Advertising Report (0x02)
        Num reports: 1
        Event type: Connectable undirected - ADV_IND (0x00)
        Address type: Public (0x00)
        Address: FF:EE:DD:CC:BB:AA
        Data length: 30
        Flags: 0x06
          LE General Discoverable Mode
          BR/EDR Not Supported
        Company: Apple, Inc. (76)
          Type: iBeacon (2)
          UUID: 669a0c20-0008-6c91-e411-015500e22ea9
          Version: 48661.62728
          TX power: -59 dB
        RSSI: -78 dBm (0xb2)
< HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2       #6 [hci0] 6.099747
        Scanning: Disabled (0x00)
        Filter duplicates: Disabled (0x00)
> HCI Event: Command Complete (0x0e) plen 4                  #7 [hci0] 6.101862
      LE Set Scan Enable (0x08|0x000c) ncmd 1
        Status: Success (0x00)
< HCI Command: LE Create Connection (0x08|0x000d) plen 25    #8 [hci0] 6.101916
        Scan interval: 60.000 msec (0x0060)
        Scan window: 60.000 msec (0x0060)
        Filter policy: White list is not used (0x00)
        Peer address type: Public (0x00)
        Peer address: FF:EE:DD:CC:BB:AA
        Own address type: Public (0x00)
        Min connection interval: 30.00 msec (0x0018)
        Max connection interval: 50.00 msec (0x0028)
        Connection latency: 0 (0x0000)
        Supervision timeout: 420 msec (0x002a)
        Min connection length: 0.000 msec (0x0000)
        Max connection length: 0.000 msec (0x0000)
> HCI Event: Command Status (0x0f) plen 4                    #9 [hci0] 6.102446
      LE Create Connection (0x08|0x000d) ncmd 1
        Status: Success (0x00)
> HCI Event: LE Meta Event (0x3e) plen 19                   #10 [hci0] 7.476997
      LE Connection Complete (0x01)
        Status: Success (0x00)
        Handle: 64
        Role: Master (0x00)
        Peer address type: Public (0x00)
        Peer address: FF:EE:DD:CC:BB:AA
        Connection interval: 48.75 msec (0x0027)
        Connection latency: 0 (0x0000)
        Supervision timeout: 420 msec (0x002a)
        Master clock accuracy: 0x00
@ MGMT Event: Device Connected (0x000b) plen 43        {0x0002} [hci0] 7.477047
        LE Address: FF:EE:DD:CC:BB:AA
        Flags: 0x00000000
        Data length: 30
        Flags: 0x06
          LE General Discoverable Mode
          BR/EDR Not Supported
        Company: Apple, Inc. (76)
          Type: iBeacon (2)
          UUID: 669a0c20-0008-6c91-e411-015500e22ea9
          Version: 48661.62728
          TX power: -59 dB
@ MGMT Event: Device Connected (0x000b) plen 43        {0x0001} [hci0] 7.477047
        LE Address: FF:EE:DD:CC:BB:AA
        Flags: 0x00000000
        Data length: 30
        Flags: 0x06
          LE General Discoverable Mode
          BR/EDR Not Supported
        Company: Apple, Inc. (76)
          Type: iBeacon (2)
          UUID: UUID
          Version: 48661.62728
          TX power: -59 dB
< HCI Command: LE Read Remote Used... (0x08|0x0016) plen 2  #11 [hci0] 7.477210
        Handle: 64
> HCI Event: Command Status (0x0f) plen 4                   #12 [hci0] 7.479342
      LE Read Remote Used Features (0x08|0x0016) ncmd 1
        Status: Success (0x00)
> HCI Event: Command Complete (0x0e) plen 14                #13 [hci0] 7.479357
      LE Read Remote Used Features (0x08|0x0016) ncmd 1
        Status: Success (0x00)
        00 00 00 00 00 00 00 00 00 00                    ..........      
> HCI Event: LE Meta Event (0x3e) plen 12                   #14 [hci0] 7.993969
      LE Read Remote Used Features (0x04)
        Status: Connection Timeout (0x08)
        Handle: 64
        Features: 0x2d 0x00 0x00 0x00 0x00 0x00 0x00 0x00
          LE Encryption
          Extended Reject Indication
          Slave-initiated Features Exchange
          LE Data Packet Length Extension
> HCI Event: Disconnect Complete (0x05) plen 4              #15 [hci0] 7.994591
        Status: Success (0x00)
        Handle: 64
        Reason: Connection Timeout (0x08)
@ MGMT Event: Device Disconnected (0x000c) plen 8      {0x0002} [hci0] 8.027693
        LE Address: FF:EE:DD:CC:BB:AA
        Reason: Connection timeout (0x01)
@ MGMT Event: Device Disconnected (0x000c) plen 8      {0x0001} [hci0] 8.027693
        LE Address: FF:EE:DD:CC:BB:AA
        Reason: Connection timeout (0x01)

连接首先成功，但随后我的设备执行“LE 读取远程使用的功能”HCI 命令，该命令在 500 毫秒后超时导致整个连接失败。

这就是我寻找上述问题答案的原因。

标签： bluetoothbluetooth-lowenergybluez

bluetooth - BlueZ LE 远程使用功能

问题描述

解决方案

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